The current proposal seeks activation of the ROO phase of a K99R00 award (1K99/ROO-DE018954). The PI has fulfilled the career goals and research aims planned for the K99 phase and is ready to move to an independent position in the ROO phase. The institutional support and environment have been instrumental for the Pi's achievements. The experimental focus of this proposal is on MMP gene variants and cleft lip with or without cleft palate (CL/P). CL/P is a common congenital anomaly that results from defects during embryonic development. The etiology of CL/P is multifactorial with multiple genetic and environmental factors assumed to be responsible. MMP genes play a significant role in the tissue remodeling required during embryonic development and may be involved in CL/P etiology. The study hypothesis is that imbalances in gene transcription due to DNA polymorphisms may alter the rates of extracellular matrix synthesis and degradation (and thus tissue remodeling) during craniofacial development and hence predispose to oral clefts. The experiments planned for the ROD follow-up on results obtained during the K99 phase of this award. Briefly, the Specific Aim. is to investigate the biological effects of the polymorphisms associated with CL/P in the K99 phase with regards to a potential role in CL/P etiology. Special emphasis wil be iven to polymorphisms in the gene promoters for their ability to regulate gene expression. Two experimental approaches will be used. Transient transfection will be used to afsess allele-dependent gene functional activity. Electrophoretic mobility shift assays (EMSA) will be used to verify protein/DNA interactions vwthin a given gene's upstream regulatory region. Understanding the functionality of disease-associated SNPs is an . important complementation and validation for genetic association studies. In the context of this proposal, any associated polymorphism that is revealed functional may provide important insights into the etiology of CL/P, and different perspectives for future research in the long-term. The proposed study constitutes ari innovative field of research adn confonns to.the initiatives of the NIH mission for future treatment possibilities.